Abstract: A method and apparatus are disclosed for implementing an optical communication network wherein switchable information signals are retained in the optical mode. Sources of optical signals, destinations for optical signals, and intermediate photonic switches are interconnected by optical links, each link comprising two unidirectional transmission optical fibers. An optical bit stream generated at a source of optical signals comprises repetitive time frames. Each time frame includes a frame synchronizing signal and a plurality of signal groups of information bits separated in time by a route switching interval. The optical bit streams entering a photonic switch are frame synchronized. A particular group of information bits retains its position in time within a frame from the source of the optical signal to its destination. The photonic switch is set up during a route switching interval for transmission of a group of information bits from an input to an output of the photonic switch.

Abstract: 23.

Abstract: A nodal switching network is disclosed wherein each node is connected to distant nodes by groups of links whose lengths are ordered to span distances definable by powers of a finite (preferably binary) integer. Starting at the calling node, a single idle link in a preferred coordinate direction is attempted to be seized to extend the connection as far as possible by a direct path. If a direct path link spanning the most of the distance in the preferred coordinate direction cannot be seized, a direct path link is attempted to be seized in another coordinate direction. If no link which would extend the connection most efficiently in either coordinate direction can be seized, links of less direct length in the coordinate directions are tested. If the call is still blocked, the procedure is repeated in the direction from the called node toward the calling node.

Abstract: A switching network containing a plurality of nodal crosspoint configurations (NCCs) through which connection paths may be established to link together a plurality of different pairs of calling and called terminating circuits is disclosed. This space division nodal network is reconfigured on each of a plurality of repetitive time slots so that the same crosspoint of a given NCC (except the crosspoints associated with the nodes's terminating circuits) may serve a different call on each time slot. Four wire paths are provided, however, to each terminating circuit by assigning separate "going" and "return" time slots to each direction of transmission. A usage count is accrued showing how many independent calls are contained in the network on each time slot. When a path for a new call is to be established, the least busy time slot is selected, and then a link path to connect calling and called terminating circuits is chosen using the least busy intervening NCCs lying in the most direct available path.

Abstract: 6. In a key pulse system for generating key pulses of definite length and highly irregular magnitude with intervening spaces, cyclically operating devices for generating groups of irregular sequences of pulses at a rate much higher than the rate of occurrence of said key pulses, each such group of pulses existing for the length of one of said spaces, and means to determine the magnitude of the next key pulse from the last pulse in the group of pulses occupying the preceding space.

Abstract: 1. In a system for transmitting a quantized signal having a definite maximum value, a reentry circuit comprising a cyclically operating electronic stepper having a cycle length in step-positions corresponding to the number of steps represented by said maximum value, and successively stepping in response to step-signal input thereto, each position of said stepper including means determinative of the generation of a respective one of three-or-more valued signals, and said circuit including means for, in effect, cancelling, once or more, from the output of said circuit a preassigned whole number of said signal steps whenever the output signal value would exceed said maximum value, and means for converting a group of different step-valued signals into a series of step-pulses to step said stepper around from an initial position through the number of steps represented by said series of pulses.13.